Electric switch



March 5, 1929. E. F. UNER` 1,704,401

ELECTRIC SWITCH Filed April 18, 1925 Patented Mar. 5, 1929,

UNITED STATES ELLSWORTH FROST MINER, OF LITCHFIELD, CONNECTICUT.

ELECT RIC SWITCH.

Application filed April 18, 1923.

'l`l invention relates to electrical circuit mah .s am breakers and, more particularly, to electric .i switches.

One of the objects of the invention is to provide an improved construction and arrangement et parts for an electric switch.

Anot' er object of the invention is to provide an improved torm ot switch which may be locked in one of its operative positions.

Another object of the invention is to provide convenient torni ot electric switch adapted to be used in connection with testing apparatus.

Still another object oit the .invention is to provide an improved :term oit electric switch having normal and alternate positions and arranged and constructed so that in order to throw the switch from normal to alternate position a specified form of key device must be used, and this key device cannot be removed from the switch until the latter has been thrown int-o normal position and locked, this key device being oi such construction that it will also prevent closing and sealing oi the switch until the key device has been removedV therefrom; all of which means that the switch cannot through negligence or deliberate intent, be closed and sealed except when the switch in normal position.

A more specilic object of the invention is, to provide an improved Jform of electric switch for use in connection with electric service meters, and which is reasonably prooi against current theft.

Other objects will be in part obvious, and in part pointed out hereinafter.

The invention, accordingly, consists in the features oi? construction, combination of elements and arrangement of parts which will be exempliiied in the construction hereinalter set iorth, and the scope ot the application oit which will be indicated in the appended claims.

In tl e drawin forming a part of the specilic tion, and in which similar reference characters reiter to similar parts.

F 1 is a plan view ol a switch embodying the 'features ot the invention and adapted to be used in connection with an electric service meter, the switch being in its normal position;

Fig. 2 is a plan view of the switch shown in its alternate or meter testing position;

Fi is a cross section o1 the switch along the line 3 3 of Fig. 1 and shows the manner Serial No. 632,932.

in Vwhich the switch blade and the contacts cri-operate.

Fig. 4 is a sectional view along the line of the locking device Fig. 1, by means of which the switch is held in its normal position, and a key plug for operating the locking device and for completing the testing circuit o'f the service meter; and

5 is a diagrammatic showing of the manne f in which the switch is associated With the current leads, service meter and the customcrs circuit.

Relier 1ing to the drawing, and more particularly to Figs. 1, 2, 3 and 4, there is illustrated lorm of switch particularly adapted for use in connection with an electric service meter the type commonly used for measuring the amount ot current consumed by the cusi'iomer vtor electric light or similar purposes. ly improved switch is susceptible of general use, but for the purpose of disclosing one of its many applications, it is here illustrated as associated with a service meter, but it is to be understood that its use is not limited thereto. The switch is housed within a suitable casing 10 and is provided with suitable bindingl posts 11, 12 and 13 which are adapted to be connected with respect to each other in a normal and alternate manner by means of a switch blade 14. i

The circuit changes effected by means of this switch make it possible to temporarily disconnect the meter from the house circuit 'for testing purposes, without interrupting the supply of current to the customer. By referring to Fig. 5, the meter, indicated at 15, may be disconnected by throwing the switch blade 14 to its alternate position, thus completing a circuit directly through terminals 11 and 13, leaving the terminal 12 disconnected from the house circuit. lVhile the circuit ot the customer is still supplied with current the meter 15 may be tested by connecting a suitable lead from the testing instrument to the terminal 12.

The switch member 14 is shaped somewhat in the form of an anchor, being pivoted at the stem end on the terminal 13, these parts corresponding to the lukes extending generally circularly about the terminal 13 as a center. The member 14 is constructed 0f conductive material, and is faced on its under side for approximately half the length of its free end with insulating material 16 soy that when thrown to its alternate position at the left 2 Lvo-5,42

the switch member is prevented Atrom contacting wit-litho terminal blade 17 upon which the terminal 12 mounted. Then in this latter position the contact face 18 on the end of the switch member is adapted to engage the terminal 11to completey a cireuit from the terminal 11 to the terminal 13 through the switch member 14. The terminal plate 17 is provided with an upwardly projecting contact face 19 which is adapted to complete the circuit from the terminal 12 through the body of the switch 14 to the terminal 13 when the switch is in its normal position. The switch member 14 is also provided with a shield or strip of insuhding inaterall which prot l s the terminal 11 Ytroni bein-9;A tampered v,-th when the switch is in its normal position. wWhen the switch thrown in its Yaldeiuiate position access to the terminal 11 is peri iitted through an aperture 22 in the strip 21 which registers with the terminal 11.

In order to prevent the switch 'from being operated by unauthorized persons, there is provided a locking` means to hold the switch in its normal position. This means comprises a latch 23 pivotally mounted on the terminal plate 17 by means of screw 24, and which is adapted to rotate into and out ot engaging relation with a stud 26 integrally formed on the lower tace ot the switch member 14. This latch 23 is adapted to be rotated by means oi a plug 27 of suitable insulatingmaterial which may be inserted through a circular aperture 28 in the switch member 14 when the latter is in its normal position. When sol inserted, a pin 29 project-ing' from the lower face et the plug@ 27 is adapted to engage with a corresponding' hole in the latch 23. Rota.-

tion of the plug' 27 will, therefore, turn the latch 23 so that it no longer engages the stud 26, ano the switch ina-y then be operated. The plug 27 is also provided with a lateral projection 31 which prevents the removal ot the plug,r from the aperture 2,8 when it has disenged the latch 23. In order that the switch blade 14 may be thrown while the plugr 27 is inserted therein, there is provided in the switch blade a slot whichis a continuation of the aperture 28, but of slightly narrower width. Grooves 33 are providedin the plug 27 so that when the plug is turned to unlock the latch 23 these grooves engage the sioes oic the slot 32 and permit throwing` of the switch 14. In this position, .the plug;` 27 can neither be turned nor removed, being held 'last by the edges oit the slot 32 engaging; in the groovesof the plug. The stud screw 34 serves as a guide for the switch member 14, and also to seeurethis member in position, there b yprovided a slot 376 with which this screw is wit-hout operating thelatch 23 by means of? the lateral projection v31, on its lower edge..

' plus; therefrom.

the latch 23 is in engagement with the stud registers with the slot 32, thus permitting the plugto be readily removable. At any other position removal of the plug is positively prevented, since the projection 31 enr ages with the lower face ot the switch member 14.

'E he plugl 27 also provides a tor conneeting a test instrument with the terminal 12 for 'the purpose ot' testii the meter 15, and to .this end there is provided a contact member within the plug which adapted to engage the head of the screw 24, and which is provided with suitably insulated cord 39 extending' throne-h the plug' 27.' for attachnient to such tes v* instrument.

The operation o'r the switch is as follows: Assuming the switch to be in its no mal operposition shown in Fig. 1, the plug 27 is inserted into the aperture 2,8 until .the pin 29 engages with the latch 23,. kThe plug then turned to disengage the latch, and the switch blade 14 is pushed to,v theleft permitting the edges of the slot 3,2 to engage the vthe meter no longer records the current used in the consumers circuit. The meter 15 is now'in condition to be tested by means of a suitable tesi'z-i'ng` instrument connectedtherewith through the conductor 39. Vilith the switch in this position, the plug;` 27 cannot he removed or rotated except on the return ot the switch blade 14 to its normal position because ot the engagement of the edges ot the 32 in the grooves 33. Upon returnin the switch to its normal position the plug; 24 may then be turned to engage the latch with the stud locking; the switch against further movement, ane permitting;- the removal of th The plug is prei'erb sr cient-tl; prev clos cover 41. rillus prevents the test i thotest pluri inserted in the switch.

A. 1 ..r' not be cle' l and sealed.

normal position, anl then rerplug, insuring' that by poss 'v v. ithont c in nv is plus; there within, the cores' through negligence, torqejnlness or can the switch hoi: be sealedv onnected; tous the con- CII with the details ot the locking mechanism to unlock the switch so that it could be thrown into its alternate position disconnecting the meter. F or this reason the` switch is practically proof against current theft and operation by liinauthorized persons.

Thus by the above construction are accomplished among others the objects here inhetore referred to.

As many changes could he made in he above corr `uctlon and many ap Virently widely diii'erent cmhmliments ot this invention could be made withoutdeparting from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted illustrative, and no,` in a limitin;` sense.

It is also understood that the language used in the 'Following claims intended to cover all or' the generic and speciiic. features ot the invention herein described and all statements ot the scope ol the invention which, as a matter ot' language, might be said to tall therebetween.

I claim as my invention:

l. In combination, an electrical switch having normal and alternate circuit making` positions, a locking device operable when said switcn is in normal position, a key member for operating said locking device and insertable in said switch when in said normal position, and easing for said switch including a cover, said key member being arranged to prevent closing of said cover when inserted in said switch.

In combination, an electrical switch having normal and alternate circuit making positions, a locking device for switch, a key member for operating said lo Vng device, and removable from Said sw. Yi only when in said normal position, and a casing for said switch including a cover, said key member being arranged to prevent closing ot said cover when inserted` in said switch.

3. ln con'ibination. an electrical switch having normal and alternate circuit making positions, a locking device for said switch, a key member tor operating said locking de- 'ice and insertable in said switch only when in said normal position and removable therefrom onli.' when said switch in normal position and said. locking dei/'ire in lockin, position, and a casing tor Said switch inchiding cover, said key member being arranged to prevent closing ol said cover' when inserted in said switch.

In combination, an electrical switch having normal and alternate circuit making positions, a locking device for said. switch, a key member for operating said locking device, insertable and removable from Said switch only lwhen in said normal position, and a casing for said switch including a cover, said key member being arranged to prevent closing of said cover when inserted in said s vitch.

ln a device of the character described, z. switch member having normal. and alternate circuit making positions, and provided with a slot therewithin, a locking device for said switch member, a key member insertal'ile in sad slotto release said locking device, and rn'orided with slots adapted to receive the of aid slot when said switch member s alternate position.

t3. in a de 7ice of the character described, a switch member pivotally mounted to move between normal and alternate circuit making positions, and provided with a slot in ,its movable end, latch to hold said switch member' in its normal position., a key meinber insertable in said slot and adapted upon rotation to release said latch, said key inember being provided with grooves to receive the edges of said slot when said switch meniber is moved from its normal position whereby said key member is held against removal except when said switch member is in its normal position.

7. In a device ot the character described, a switch member pivotally mounted to move between normal and alternate circuit n'iaking positions, and provided with a slot. in its movable end, a latch to hold said switch member in its normal position, a key member insertable in said slot and adapted upon rotation to release said latch, said key member being provided with grooves adapted to receive the side edges of said slot when said switch member is moved from its normal position, whereby said key member is held against removal except when said switch member is in its normal position, and means associated with said key member and co-operative with said switch member to prevent the removal of said key member from said switch member when said latch is released.

8. In a device of the character described, a switch member having normal and alternate circuit making positions, a normal contact and an alternate contactt-herefor, and a shield carried by said switch member to cover said alternate contact when said switch member is in its normal position.

S). In a device ot the character described, a switch member having normal and alternate circuitm. king positions, a normal contact and an alternate contact therefor, said switch member con'rprising portions adapted to contact with said normal and alternate contacts, an insulating portion to prevent contact with said normal Contact when said switch member is in its alternate position, and a shield to protect said alternate contact when said switch member is in its normal position.

10. In a device of the character described, a switch member having normal and alten nate circuit making positions and provided with a` Slet therein, normal :iii-fl alterna@ Qonleets for said Switch memberu :i leelriv l; device t0 held seid switch member in ire normal position, and a circuit making plug lrey meer ber infiertalfle in said Slot to engage one of said contacts, and aflaped to release seid. locking device, and means )5o hold smid plug; againe removal from said cenae when said switch member is out 01 its normal por' ion.

1l. ii a device o'i' lie char eier (jlescri'bed a switch member lim/'ing Dermal e d zilierr .ie circuit making positions and previclel lili a slot thereini Herma] and alueiiiae eoiitzaeis for said switch member, a locking device te hold said switch member iii ie normal peeition7 and :i Circuit making plug key ineiler inserable in Said slet to contL with one 0il said coiitacis and erleped le diseagege said locking device, said plug beingproviclel with p l Circuit making plug key mein.h b with elle er insertable in Said slet te floured; Seid Sommers sind Clziptee cliserigege said @cking cleviee, Seial plug being revidefl with 'rom/es io be engaged by said switch member when the leiter f neriiizl posiion,

and a lateral pregee-ieii en said plug' to pie removal thereof from sail slot except when said device is in its locking pesiion and smid Switch is in its normal pOSi-iozi.

ELLSVURTH FROST MNER. 

